A typical fuel cell power system includes a power section in which one or more stacks of fuel cells are provided. The efficacy of the fuel cell power system depends in large part on the integrity of the various contacting and sealing interfaces within individual fuel cells and between adjacent fuel cells of the stack.
To achieve the power needed for some implementations, a fuel cell stack can include large numbers of membrane electrode assemblies (MEAs), flow field plates, and sealing gaskets. These and other components of the stack must be carefully aligned and assembled. Misalignment of even a few components can lead to gas leakage, hydrogen crossover, and performance/durability deterioration.
The durability of the fuel cell membrane during extended operation often determines whether fuel cells can be used cost effectively. Although an MEA can fail in a number of ways, one typical failure mechanism is excessive gas crossover caused by the puncture of the membrane or repetitive physical deformation at an edge of the active area due to swelling and shrinkage of the membrane with humidity cycling.
There is a need for an MEA having an improved durability and lifetime. The present invention fulfills these and other needs.